<style type="text/css">
    div {
        width: 300px;
        height: 200px;
        border: 1px solid #EEEEEE;
        margin: 50px auto;
        overflow: hidden;
        cursor: pointer;
    }

    img {
        width: inherit;
        height: inherit;
        object-fit: cover;
    }

    .scale-big {
        /* 变化时间 */
        transition: all 1s;
    }

    .scale-big:hover {
        /* 比例放大 */
        transform: scale(1.12);
    }
</style>

<div>
    <img class="scale-big" src="demo.png" />
</div>